The first manufacturer has been producing Opaque Quartz Glass Tube in China. It has no any harmful radiation, and it is characterized by high temperature resistance, good thermal stability, free selection of heating temperature, and no change in radioactivity for long terms of use, long service life, reasonable structure, convenience in use and less thermal inertia, etc. Also, they have some functions of transparent quartz glass tubes. Furthermore, they are used as their far-infrared reflection materials.

The Out-diameter deviation of the Opaque quartz glass tube should not be over the stipulations in Table 1

Range of Out-Diameter

8 16

17 25

26 35

36

Out-Diameter Deviation

0.30

0.50

0.70

1.00

Note:

1. the tubes, with both end open and one end open, are available. The Out-diameter of the dome end, if so, should not be over the Out-diameter of the tube.

2. For the tubes with special dimensions, it needs to be discussed by the both sides of supplier and customer.

The Wall Thickness deviation of the Opaque quartz glass tubes should not be over the stipulations in Table 2

Range of Wall thickness

0.8~1.5

1.6~3.0

3.1

Deviation of Wall Thickness

0.10

0.20

0.30

Note:

1. The tubes, with both end open and one end open, are available. The wall thickness of the dome end, if so, should not be less than three-fourth of the wall thickness of the tube.

2. For the tubes with special dimensions, it needs to be discussed by the both sides of supplier and customer.

The other requirements to the Opaque quartz glass tubes should be in accordance with the stipulations in Table 3

Elliptcity

Not over the absolute value of OD deviation

Length

Decided by the supplier and customer, however the tolerance should not be over ±1mm

Deviation of Wall Thickness

Not over the absolute value of wall thickness deviation

Angularity

Not over 3% of the tube length

Surface Dirties

There must not be dirties on the inner surface. Without any obvious finger prints. Without obvious adhered materials caused when cutting; within the range of 300mm, obvious concentrated area of water marks cause when cutting should not be more than one; within the range of 300mm, the inner dirty area and small dirty pits should not be over 2mm.

Scuffings and Nicks

The total axial-direction scuffing length should not be over two times of the total length of the tube; and the total round scuffing length should not be over two times of the circumference of the tube. The length of the nick should not be over 12.5mm within the range of 300mm, and the nick length should not be over the circumference of the tube.